SR20DET warm start/ cold start smoke problem

[Don102]

Hi all.

I got a strange problem. I think it was longer around, but noticed it more and more. It's a '96 SR20DET S14. Don't know if the two problems are related, but will explain those anyway.

Problem 1

When I cold start, and drive away it runs good, boost good, idle good, no issue's at all. After driving a while, park the car, and start the car again after 15min, sometimes it runs very bad idle. Still drivable, but you notice it sometimes almost want to stall idle. Two times it just died when I was braking, or steering. After driving a little, it runs OK again, only with higher idle (~1200rpm instead of ~750rpm) and the backfire is also gone, bur drivable

Turn it off, and let it for some hours cool down, it start perfect again with no issues.

Problem 2

Starting the car, drive for 2 min until the traffic light. If i should wait a little longer I notice some grey/blue smoke coming out, smelling really weird too. Strange thing, it doesn't use any oil, only I noticed the coolant going lower, but nothing strange on my oil or under the radiator cap. After driving it a little the smoke is gone. But sometimes come back when I idle it for a little bit long.
Think to do a compression test to see if my head gasket is still ok.

So if you guys have a clue how to solve the problems, let me know. Thanks!

[1nasty240sx]

Do a compression test
Boost leak test
Recirculate your blow off valve
Your headgasket could be blown
Your turbo could be shot as well
So just check all those things I just said:D

[OrangeVirus1]

I had this same problem with my eclipse once. coolant temp sensor was bad, and giving crazy erratic readings to the ECU

[Don102]

Do a compression test
Boost leak test -> CHECK, no leaks
Recirculate your blow off valve -> CHECK, pidgin mod
Your headgasket could be blown
Your turbo could be shot as well
So just check all those things I just said:D

Will check for the other things, thanks! :)

I had this same problem with my eclipse once. coolant temp sensor was bad, and giving crazy erratic readings to the ECU

Could be the fault. Just thinking, sometimes when it was running high idle it just rev (like you tap the throttle for a sec). and run like normal again.

[OrangeVirus1]

you'd be surprised what a bad temp sensor would make a car do..

even though many people think coolant sensors aren't important, most cars use this temp signal to choose from various maps,timing, fueling, ignition etc. it isn't just a "oh I'm warm, Oh I'm cold" type of deal.

[jr_ss]

You sir have a leaking headgasket... Using coolant and white/bluish smoke are classic signs. Do a hydrocarbon test to confirm it.

[Dro]

Easy way to tell if the HG is leaking, look at your coolant tank. If your coolant has brown in it then you know it is in fact leaking.

Problem #1 could be caused by your timing being off, or even a defective ECT Sensor.
You said something about a backfire?

Leaking valve seals can cause problem #2 in my experience, my car did the same if it idled for too long.
A leak-down and compression test should tell you everything you need to know but test the ECT sensor first, as it is very easy to do with a DMM.

[carlos-s14sr20]

@ don102 i had almost the same problem with my sr smoking every time i came to a traffic light I replace the head gasket and replace my valve seals and my problem stopped my car idles perfect and runs good. so you might have the same problem..